Change cancellationDetails document to not required

STR:

1. Pulish SSW procedure
2. Try to cancel procedure with body

{
    "reason": {
        "uk_UA": "Якась причина скасування аукціону"
    },
    "datePublished": {{datePublished}}
}

AR:
error message

 "message": {
        "documents": "This field is required"
    }

ER:
procedure status changes to cancelled